Growth of equiaxed dendritic crystals settling in an undercooled melt
نویسندگان
چکیده
Experiments were conducted to measure the dendrite tip growth velocities of equiaxed dendritic crystals settling in an undercooled succinonitrile (SCN)-acetone melt. The tip velocities were measured as a function of the settling speed of the crystal and the Eulerian angle between the dendrite arms and the flow direction relative to the crystal. The average of the measured tip growth velocities of all six dendrite arms of an equiaxed crystal was found to be in excellent agreement with the standard diffusion theory result. The individual tip velocities were correlated using a boundary layer model of free dendritic growth in the presence of melt flow that was modified to account for the flow angle dependence. The model is found to predict well the variations in the tip velocity that occur during settling due to crystal rotation and settling speed changes.
منابع مشابه
Validation and Simulation of Cellular Automaton Model for Dendritic Growth during the Solidification of Fe–C Binary Alloy with Fluid Flow
Based on our previous developed 2D CA-FVM model, where the transport phenomna and kinetics conditions of solute-driven dendritic growth occurred in the solidification process with fluid flow were totally taken into consideration, an extensive model validation and furhter model application are demonstrated here. Firstly, the flow pattern of the lid-driven cavity is well predicted and quantitativ...
متن کاملModeling of coupled motion and growth interaction of equiaxed dendritic crystals in a binary alloy during solidification
Motion of growing dendrites is a common phenomenon during solidification but often neglected in numerical simulations because of the complicate underlying multiphysics. Here a phase-field model incorporating dendrite-melt two-phase flow is proposed for simulating the dynamically interacted process. The proposed model circumvents complexity to resolve dendritic growth, natural convection and sol...
متن کاملMacroscopic Model for Predicting Columnar to Equiaxed Transitions using Columnar Front Tracking and Average Equiaxed Growth
A macroscopic model of Columnar-to-Equiaxed Transition (CET) formation is presented. The growth of a columnar zone and an equiaxed zone are treated separately and modeled on a fixed grid. The model uses a columnar Front Tracking (FT) formulation to compute the motion of the columnar front and the solidification of the dendritic columnar mushy zone. The model for the equiaxed zone calculates the...
متن کاملDendrite Growth Kinetics in Undercooled Melts of Intermetallic Compounds
Solidification needs an undercooling to drive the solidification front. If large undercoolings are achieved, metastable solid materials are solidified from the undercooled melt. Containerless processing provides the conditions to achieve large undercoolings since heterogeneous nucleation on container walls is completely avoided. In the present contribution both electromagnetic and electrostatic...
متن کاملEquiaxed Dendritic Solidification with Convection Part I. Multiscale/Multiphase Modeling
Equiaxed dendritic solidification in the presence of melt convection and solid-phase transport is investigated in a series of three articles. In part I, a multiphase model is developed to predict composition and structure evolution in an alloy solidifying with an equiaxed morphology. The model accounts for the transport phenomena occurring on the macroscopic (system) scale, as well as the grain...
متن کامل